package main

import (
  "encoding/json"
  "errors"
  "flag"
  "fmt"
  "log"
  "net/http"
  "net/url"
  "os"
  "regexp"
  "strings"
  "time"

  "github.com/gempir/go-twitch-irc/v4"
)

var COMMAND_RE = regexp.MustCompile(`^(\$|!)([a-z_]+) ?(.*)?$`)

type Secret struct {
  ClientID string
  ClientSecret string
  AccessToken string
  RefreshToken string
}

type Periodic struct {
  Seconds int
  Message string
}

type Config struct {
  ClientNick string
  Channel string
  Commands map[string]string
  Actions map[string]string
  Periodic []Periodic
}

type Poll struct {
  Active bool
  Text string
  Yes int
  No int
}

type Bot struct {
  Secrets Secret
  Config Config
  Client *twitch.Client
  CurrentPoll Poll
}

type Command struct {
  Type string
  Command string
  Text string
}

type TwitchTokenResponse struct {
	AccessToken  string   `json:"access_token"`
	RefreshToken string   `json:"refresh_token"`
	ExpiresIn    int      `json:"expires_in"`
	Scope        []string `json:"scope"`
	TokenType    string   `json:"token_type"`
}

func LoadJSON[T any](file string) T {
  data, err := os.ReadFile(file)
  if err != nil { log.Fatal(err) }

  var config T
  err = json.Unmarshal(data, &config)
  if err != nil { log.Fatal(err) }

  return config
}

func RunPeriodic(message Periodic, channel string, client *twitch.Client) {
  for {
    time.Sleep(time.Duration(message.Seconds) * time.Second)
    client.Say(channel, message.Message)
  }
}

func (bot *Bot) RefreshToken() {
  api_url := "https://id.twitch.tv/oauth2/token"
  data := url.Values{}
  data.Set("client_id", bot.Secrets.ClientID)
  data.Set("client_secret", bot.Secrets.ClientSecret)
  data.Set("grant_type", "refresh_token")
  data.Set("refresh_token", bot.Secrets.RefreshToken)

  encoded := strings.NewReader(data.Encode())
  resp, err := http.Post(api_url,"application/x-www-form-urlencoded", encoded)

  if err != nil { log.Fatal(err) }

  defer resp.Body.Close()

  if resp.StatusCode != http.StatusOK {
    log.Fatal(fmt.Sprintf("Invalid status code: %v.", resp.StatusCode))
  }

  var token_resp TwitchTokenResponse
  err = json.NewDecoder(resp.Body).Decode(&token_resp)
  if err != nil { log.Fatal(err) }

  bot.Secrets.AccessToken = fmt.Sprintf("oauth:%s", token_resp.AccessToken);
}

func (bot *Bot) LoadConfigs() {
  var secrets_file string
  var config_file string
  var action_file string

  flag.StringVar(&secrets_file, "secrets", "secret.json", "Your secrets file. KEEP PRIVATE!")
  flag.StringVar(&config_file, "config", "config.json", "Your config.json. Can be public.")
  flag.StringVar(&action_file, "actions", "actions.json", "Your URL actions. KEEP PRIVATE!")
  flag.Parse()

  log.Println("Loading secrets from", secrets_file)
  log.Println("Loading config from", config_file)
  log.Println("Loading actions from", action_file)

  bot.Secrets = LoadJSON[Secret](secrets_file)
  bot.Config = LoadJSON[Config](config_file)
  bot.Config.Actions = LoadJSON[map[string]string](action_file)
}

func ParseCommand(message string) (Command, error) {
  matches := COMMAND_RE.FindStringSubmatch(message)

  if matches == nil {
    return Command{}, errors.New("Invalid command format.")
  }

  result := Command{
    matches[1],
    matches[2],
    matches[3],
  }

  return result, nil
}

func (bot *Bot) StreamerAction(message twitch.PrivateMessage) {
  if !message.User.IsBroadcaster {
    log.Println("! A StreamerAction message was sent by someone not marked as Broadcaster")
    return
  }

  cmd, err := ParseCommand(message.Message)
  if err != nil {
    fmt.Println(err)
    return
  }

  switch cmd.Command {
  case "poll_start":
    if cmd.Text == "" { return }

    bot.CurrentPoll.Active = true
    bot.CurrentPoll.Text = cmd.Text
    bot.CurrentPoll.Yes = 0
    bot.CurrentPoll.No = 0

    announce := fmt.Sprintf("New Poll: %s. Use 1, yes or true; 0, no or false to reply.", bot.CurrentPoll.Text)

    bot.Send(message, announce)
  case "poll_end":
    bot.CurrentPoll.Active = false
    bot.CurrentPoll.Text = fmt.Sprintf(
          "Poll Has Ended: \"%s\" Yes=%d, No=%d",
            bot.CurrentPoll.Text, bot.CurrentPoll.Yes, bot.CurrentPoll.No)
    bot.Send(message, bot.CurrentPoll.Text)
  }
}


func (bot *Bot) TryPoll(message twitch.PrivateMessage) bool {
  switch message.Message {
  case "yes", "1", "true":
    bot.CurrentPoll.Yes += 1
    return true
  case "no", "0", "false":
    bot.CurrentPoll.No += 1
    return true
  }

  return false
}

func (bot *Bot) Send(message twitch.PrivateMessage, text string) {
  bot.Client.Say(message.Channel, text)
}

func (bot *Bot) Reply(message twitch.PrivateMessage, text string) {
  bot.Client.Reply(message.Channel, message.ID, text)
}

func (bot *Bot) SendHelp(message twitch.PrivateMessage) {
  bot.Reply(message, "Invalid command. Use !help to see what's available.")
}

func (bot *Bot) ViewerAction(message twitch.PrivateMessage) {
  cmd, err := ParseCommand(message.Message)
  if err != nil || cmd.Type != "!" {
    bot.SendHelp(message)
    return
  }

  switch cmd.Command {
  case "poll":
    if bot.CurrentPoll.Active {
      bot.Reply(message,
        fmt.Sprintf("Current Poll: %s, Yes=%d, No=%d",
          bot.CurrentPoll.Text, bot.CurrentPoll.Yes, bot.CurrentPoll.No))
    } else {
      bot.Reply(message, "No poll currently active.")
    }
  default:
    // see if it's a normal command
    reply, valid_cmd := bot.Config.Commands[strings.ToLower(cmd.Command)]

    if valid_cmd {
      bot.Reply(message, reply)
    } else if !valid_cmd {
      bot.SendHelp(message)
    }
  }
}

func (bot *Bot) HandleMessage(message twitch.PrivateMessage) {
  // not sure if this is good enough for auth
  if strings.HasPrefix(message.Message, "$") && message.User.IsBroadcaster {
    bot.StreamerAction(message)
  } else if bot.CurrentPoll.Active && bot.TryPoll(message) {
    return
  } else if strings.HasPrefix(message.Message, "!") {
    bot.ViewerAction(message)
  }
}

func (bot *Bot) CreateClient() {
  // or client := twitch.NewAnonymousClient() for an anonymous user (no write capabilities)
  bot.Client = twitch.NewClient(bot.Config.ClientNick, bot.Secrets.AccessToken)

  bot.Client.OnPrivateMessage(func (message twitch.PrivateMessage) {
    bot.HandleMessage(message)
  })

  bot.Client.OnSelfJoinMessage(func (message twitch.UserJoinMessage) {
    log.Println("Join", message.Channel, "as", message.User, "successful")
  })

  bot.Client.OnConnect(func () {
    log.Println("Connected. Joining", bot.Config.Channel)
    bot.Client.Join(bot.Config.Channel)
  })

  bot.Client.OnNoticeMessage(func (message twitch.NoticeMessage) {
    log.Println("NOTICE", message.Channel, message.Message)
  })
}

func (bot *Bot) RunPeriodic() {
  for _, perodic := range(bot.Config.Periodic) {
    go RunPeriodic(perodic, bot.Config.Channel, bot.Client)
  }
}

func (bot *Bot) Connect() {
  log.Println("Connecting to Twitch...")
  err := bot.Client.Connect()
  if err != nil { log.Fatal(err) }
}

func CreateBot() *Bot {
  var bot Bot

  bot.CurrentPoll.Active = false
  bot.LoadConfigs()
  bot.RefreshToken()
  bot.CreateClient()

  return &bot
}

func main() {
  bot := CreateBot()
  bot.RunPeriodic()
  bot.Connect()
}